The Pulse Echo Test, also known as Pile Integrity Test, Sonic Echo Test and Low Strain Impact Integrity Test, is a rapid, inexpensive, non-destructive method to check for pile defects such as voids, cracks, necking, inclusions, etc. It determines the pile integrity, dimensions, continuity and pile material consistency by measuring and analyzing the velocity response of the pile induced by the impact of a hand held hammer applied axially and perpendicular to the pile head surface. The stress wave induced by the hammer strike travels down the pile shaft and reflected waves from significant changes in pile shaft acoustic impedance are registered by a transducer held against the pile head.
Measured signals are amplified, digitized and stored by the test unit. The data from the test unit is used by computer software to generate velocity-time graph as shown on the next page. Trained technicians interpret such graphs to determine if the pile has any serious defects, allowing quick evaluation and enhancing the reliability of the foundation.
